Brent Robson, a county commissioner from Tetonia, Idaho and an experienced snowmobiler, was leading a group of snowmobilers one day in 1998 when, without warning, his machine violently lurched into the air before coming to a rest in the bottom of a 15-foot pit. Robson broke his back and had to spend 12 weeks in a cast and go through extensive physical therapy.

He later learned that the pit that nearly killed him had been constructed by the U.S. Forest Service. The Forest Service has been constructing these pits - or in the words of Idaho Congressman Helen Chenoweth-Hage, "tank traps" - to prevent snowmobiles and other vehicles from accessing the 400 miles of public roads in the Targheee National Forest. Each trap has a 15-foot earthen wall and a 15-foot pit. There are no signs posted to warn recreational users about their location. In fact, the trap that almost killed Robson was in the middle of an ordinary forest road. Because there was snow on the ground, the unmarked trap was nearly invisible.

Outraged by this blatant disregard for public safety, Congressman Chenoweth-Hage sharply questioned Forest Service chief Mike Dombeck and Undersecretary of Agriculture Jim Lyons about the service's policy in a February 1999 hearing. Lyons originally claimed that the traps were intended to protect elk and grizzly bears. The Forest Service's Dombeck finally agreed that the traps posed a serious safety problem and promised to look into the matter.
Source: Rep. Helen Chenoweth-Hage